This is false. Deflation does not encourage hoarding. The argument that deflation encourages hoarding works just as well to argue the deflation encourages spending.
Reality does not agree with you, people are hoarding bitcoins like crazy.
Logic does not agree with you. Bitcoins aren't deflationary* until 2031. At present they are inflationary (more are being minted every day).
How do you reconcile that with
inflationary = spend; deflationary = hoarde? The answer is that it's more complicated than that.
(In truth bitcoins aren't deflationary at all, they will be static)